Notenik is a desktop software program to help a single user maintain multiple collections of notes. You may well ask why the world needs yet another note-taking app and, in truth, I'm not sure it does.
However, whether it wants or needs one or not, it has one, and so I will try to explain why I've have labored to give birth to such a thing at this late date. Each note stored as a plain text file. This ensures that the notes can be edited on any device, by any text editor, and allows the notes to be painlessly synced between devices using a service such as Dropbox. Ability to handle multiple collections of notes. I really don't want to be limited to a single collection. With Notenik, create as many folders of notes as you like. Embedded, platform-independent tags. I want to be able to tag my notes, and see them organized by tags, but I want the tags to move with the notes when the notes get synced between devices, and I want the tags to be editable with any text editor that can be used to edit the notes themselves. Bookmarks too. Add a URL to a note, and it becomes a bookmark. So now I can create a separate folder just for bookmarks, and organize them by tags, all with the same little app. A file format that is simple to read and simple to edit. No XML, no HTML, just some flexible, quasi-markdown formatting.